1. Automatic Transmissions Products
  2. sku: 23494501806438793
  3. NISSAN 31020-7BM1A

NISSAN 31020-7BM1A Trans Axle Automatic

fits make: Nissan.

31020-7bm1a Nissan Genuine Trans-axle Assembly Automatic

( Manufacturer Part Number: 31020-7BM1A ), ( Part Type: Tran Axle ), ( Genuine Oem: Yes ), ( Manufacturer Warranty: 1 Year ), ( Fitment Type: Direct Replacement ), ( Parts Included: Only Part Reference 0 On The Diagram Is Included ), ( Replaces Part Number: 310207ba1a, 310207ba2a, 310207bm0a )

Review NISSAN Genuine Trans axle Assembly Automatic

The **Nissan 31020-7BM1A Trans-Axle Automatic** is a high-performance, precision-engineered transmission module designed exclusively for Nissan s front-wheel-drive vehicles, offering seamless integration with the powertrain for optimal drivability and efficiency. This trans-axle assembly combines an automatic transmission with an integrated differential, eliminating the need for a separate transfer case or driveshaft, which simplifies the drivetrain architecture while maintaining robust performance. Built with a robust **Jatco-built CVT (Continuously Variable Transmission)** core, this unit features a **7-speed automatic transmission** with advanced hydraulic and electronic controls, ensuring smooth gear shifts, enhanced fuel economy, and responsive acceleration ideal for both urban commuting and highway cruising. The transmission incorporates a **torque converter** with a lock-up clutch mechanism, which optimizes efficiency by engaging directly with the engine at higher speeds, reducing energy loss and improving overall performance.

The **31020-7BM1A** is engineered for compatibility with Nissan s **CVT-based powertrains**, commonly found in models such as the **Altima, Sentra, Maxima, and Rogue**, among others, though its robust design makes it a reliable choice for applications requiring durability and reliability. Its compact yet sturdy construction includes a **spiral-bevel differential** with a limited-slip feature, ensuring balanced power delivery to the front wheels while maintaining stability during cornering and acceleration. The unit is equipped with a **hydraulic valve body** and **electronic shift solenoids**, allowing for precise control over gear engagement and fluid pressure, which contributes to the transmission s longevity and adaptability to varying driving conditions.

For maintenance and longevity, the **31020-7BM1A** relies on a **high-quality automatic transmission fluid (ATF)**, typically **Nissan NS-2 or NS-3**, which lubricates internal components, dissipates heat, and protects against wear. Regular fluid changes and filter replacements are critical to preventing sludge buildup and ensuring smooth operation. Additionally, the transmission incorporates **sealed bearings, synchronizers, and a reinforced housing**, designed to withstand the stresses of daily driving, aggressive acceleration, and towing (when applicable). Its **compact yet durable design** also makes it a favored choice for customization projects, where enthusiasts may opt for upgraded clutches, cooler fluid systems, or reinforced differentials to enhance performance.

Whether installed in a stock application or as part of a performance upgrade, the **Nissan 31020-7BM1A Trans-Axle Automatic** delivers a harmonious blend of efficiency, reliability, and adaptability. Its seamless integration with Nissan s front-wheel-drive platforms ensures minimal drivetrain complexity while maximizing power transfer, making it a cornerstone component for both factory-equipped vehicles and aftermarket modifications. With proper care and maintenance, this transmission module provides years of trouble-free service, embodying Nissan s commitment to engineering precision and performance in automotive drivetrain technology.

### **Pros and Cons of Buying a Nissan 31002-7BM1A Trans-Axle (Automatic)**

The **Nissan 31002-7BM1A** is a transaxle (transmission differential combined) commonly found in older Nissan models like the **Altima (VQ35DE engine)** and some **Maxima** variants. Below is a detailed breakdown of its advantages and drawbacks.

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### **Pros**

1. **Compact and Space-Efficient Design**

- The transaxle integrates the transmission and differential into a single unit, reducing overall vehicle length. This is particularly useful in front-wheel-drive (FWD) applications where space is limited.

2. **Proven Reliability in Nissan Applications**

- This transaxle was used in several Nissan models (Altima, Maxima, Sentra) from the late 1990s to early 2000s. Many owners report smooth operation when properly maintained.

3. **Common Availability of Parts**

- Being a Nissan component, replacement parts (seals, bearings, synchronizers, solenoids) are widely available, though pricing can vary depending on demand.

4. **Compatibility with Aftermarket Modifications**

- Since it s a popular transaxle, tuners and mechanics have developed aftermarket upgrades (e.g., clutch kits, torque converter swaps) to improve performance.

5. **Lower Cost Compared to Full Transmissions**

- In some cases, a transaxle can be cheaper to repair than a standalone transmission, especially if the differential is still functional.

6. **Easy to Remove and Replace**

- The design allows for straightforward removal, which can be an advantage for DIY mechanics or those looking to swap in a used unit.

---

### **Cons**

1. **Aging and Wear Issues**

- Many units in circulation are **15 years old**, leading to common problems like:

- **Leaking seals** (front and rear)

- **Worn synchronizers** (leading to rough shifting)

- **Faulty torque converter** (common in automatic versions)

- **Bearing failure** (especially in the differential section)

- Older units may require frequent fluid changes and inspections.

2. **Electrical and Solenoid Problems**

- The **automatic version** relies on solenoids and a valve body, which can fail over time, causing erratic shifting or complete transmission lockup.

3. **Limited Longevity Under Heavy Use**

- While capable of lasting **150,000 200,000 miles** with proper maintenance, **high-performance or towing applications** can accelerate wear, especially in the differential section.

4. **Difficulty Finding a High-Mileage but Reliable Unit**

- Many transaxles sold as "used" have **hidden damage** (bent shafts, cracked cases) due to improper storage or abuse. A thorough inspection is essential.

5. **Specialized Repair Knowledge Required**

- Unlike a standalone transmission, the **differential section** adds complexity. Mechanics unfamiliar with transaxles may charge more for repairs.

6. **Potential for Hidden Damage**

- Since the transaxle combines transmission and differential, **internal damage in one area can affect the other**. For example:

- A **bent output shaft** can damage the differential bearings.

- **Fluid leaks** can lead to **differential failure**, causing the entire unit to seize.

7. **Limited Warranty Options**

- Most used transaxles come with **no warranty**, and even new ones may not have a long-term guarantee unless purchased from a dealership.

---

### **Common Symptoms of a Failing 31002-7BM1A**

Before purchasing, watch for:

- **Grinding or clunking noises** (indicates worn synchronizers or bearings).

- **Slipping gears** (weak clutch pack or torque converter failure).

- **Fluid leaks** (from seals around the output shaft or differential).

- **Delayed engagement** (faulty solenoid or valve body).

- **Overheating** (common in automatic versions due to poor cooling).

---

### **Conclusion**

The **Nissan 31002-7BM1A transaxle** is a **practical and space-efficient** component for FWD applications, especially in older Nissan models. It offers **good reliability if maintained properly** and benefits from **widespread part availability**. However, its **aging design, common wear issues, and complexity** make it a **high-risk purchase for inexperienced buyers**.

If you **plan to use it in a well-maintained vehicle with moderate mileage** and are **prepared for potential repairs**, it can be a **cost-effective solution**. However, if you re looking for **long-term reliability without major upkeep**, a **new or rebuilt transmission** (such as a **Jatco JF511E** or **Aisin TF80SC**) may be a safer alternative.

---

### **Recommendation**

1. **If Buying Used:**

- **Get a professional inspection** (preferably from a Nissan specialist).

- **Check for fluid leaks, strange noises, and smooth shifting** before purchasing.

- **Consider a rebuilt unit** from a reputable shop (e.g., **Transmission Super Center, JE Crouse**) if you want better reliability.

- **Budget for potential repairs** (clutch pack, torque converter, seals).

2. **If Considering a Replacement:**

- **For a used car**, pair this transaxle with a **low-mileage engine** (VQ35DE) to maximize longevity.

- **For a project car**, weigh whether the **cost of repairs** justifies the transaxle s benefits.

- **If performance is a priority**, explore **aftermarket upgrades** (e.g., **torque converter swaps, clutch kits**) to improve durability.

3. **Best Alternative Options:**

- **Jatco JF511E** (used in later Altimas, more reliable but pricier).

- **Aisin TF80SC** (common in Japanese imports, durable but requires proper fluid).

- **Rebuilt Nissan CVT** (if considering modern Nissan models).

**Final Verdict:**

The **31002-7BM1A is a viable choice for budget-conscious buyers willing to accept maintenance risks**, but **not ideal for those seeking hassle-free longevity**. If you re comfortable with **regular inspections and potential repairs**, it can be a **good fit for a well-used Nissan**. Otherwise, investing in a **rebuilt or newer transmission** may be the smarter long-term choice.

Details:

Shipping Carrier substitutions may be made at our determination in an attempt to reduce shipping cost the customer. Parts must be resalable and in the original packaging. Whether you re restoring a classic, upgrading performance, or maintaining your daily driver, our team is here to help. Electrical parts are not returnable.

part #: 310207bm1a prices

  • $4812.88-$4951.26

specifications autotransmissionsgo:

  • for makes: Nissan
  • mpn: 31020-7bm1a
  • part type: Tran Axle
  • genuine oem: Yes
  • manufacturer warranty: 1 Year
  • fitment type: Direct Replacement
  • parts included: Only Part Reference 0 On The Diagram Is Included
  • replaces part number: 310207ba1a, 310207ba2a, 310207bm0a

general autotransmissionsgo:

  • Car Truck Parts Accessories > Transmission Drivetrain > Automatic Transmission
  • condition: New

offer autotransmissionsgo:

  • sold: 0
  • availability: In Stock
  • started: April 13, 2026
  • options: Ship-to-home
  • quantity: 1

seller autotransmissionsgo:

  • rating: 99.7%
  • city: Dallas, Texas
  • # reviews: 4519

payments autotransmissionsgo:

  • wallet: Apple-pay
  • other
  • credit card: Discover

returns autotransmissionsgo:

  • time: 30 Days
  • policy: Returns Accepted
  • paid by: Seller

shipping autotransmissionsgo:

  • class: Freight
  • service: Flat Rate Freight
  • cost: $503.99
  • type: Fixed
for makes: nissan, part type: tran axle, genuine oem: yes, manufacturer warranty: 1 year, fitment type: direct replacement, parts included: only part reference 0 on the diagram is included, replaces part number: 310207ba1a, 310207ba2a, 310207bm0a,
category: auto parts > car truck parts accessories > transmission drivetrain > automatic transmission, sku: 23494501806438793,
Nissan 31020-7BM1A Is Similar To:
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2 offers $4812.88–$4951.26 USD
  • New. Offer #1 priced at $4951.26 + $503.99 shipping estimate = $5455.25* total. Whether you re restoring a classic, upgrading performance, or maintaining your daily driver, our team is here to help Genuine Nissan Parts.+$503.99 shipping
  • New. Offer #2 priced at $4812.88 + $234.00 shipping estimate = $5046.88* total. +$234.00 shipping

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